The proposed research contrasts the course of unipolar depressive disorders for outpatients treated in three systems of care: solo fee-for-service; prepaid group practices and; mixed prepaid and fee-for-service multispecialty group practices. The rapid growth of prepaid systems enhances the importance of obtaining data on their effects, relative to fee-for-service care. The research also contrasts the course of depression for patients treated by mental health specialists and general medical physicians. Depressive disorders are among the most common disorders treated in both medical and psychiatric settings. For patients of general medical physicians, the course of depression is compared for those who have depression alone and those who have depression and either hypertension, diabetes mellitus, or recent myocardial infarction. These are three of the most prevalent chronic medical diseases treated in all health care settings. Their impact on course of depressive illness is virtually unstudied. The research would supplement the National Study of Medical Care Outcomes (MOS), funded by the Robert Wood Johnson and Henry J. Kaiser Foundations. In this study, 3200 adult patients with depressive disorder and/or one of the three medical conditions noted above will be selected from the three systems of care in four geographic sites. Data on use of health services and general health status will be collected prospectively for two years beginning in January, 1986. The proposed work requests funding for collecting data on course of depressive illness over the two year study period (monthly depression symptom checklists and utilization reports and semi-annual telephone interviews using an adaptation of the Diagnostic Interview Schedule of NIMH); and for analyses of the effects of system of care, type of provider, and presence or absence of chronic medical illness on course of depressive disorder. Comparability of groups at baseline in characteristics of depression, other psychiatric disorders, and physical health status will be examined in detail and controlled for in statistical analyses.